Abstract

Brillouin scattering spectra, with a single mode argon-ion laser and triple-pass Fabry-Perot interferometer, have been measured for natural biological fibres and for films of synthetic polypeptides. For wet unstretched rat tail collagen, with the scattering vector parallel and perpendicular to the fibre axis, single Brillouin shifts of ± 7.9 GHz and ± 6.3 GHz respectively were observed. With the scattering vector at 45° to the fibre axis, two peaks ( ± 6.35 GHz and ± 7.7 GHz) were found. For horse hair keratin the shifts for the scattering vector parallel and perpendicular to the fibre axis were ± 8.7 GHz and ± 7.7 GHz respectively. A single peak only was found with the vector at 40° to the fibre axis. Two synthetic polypeptides poly(DL-caprylic acid) and poly(Y-ethyl-L-glutamate), known to have the a-helix conformation, gave shifts of ± 6.36 and ± 6.1 GHz. The results are discussed.

Footnotes

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